The Toronto-based electronics manufacturer says it will start the hunt immediately for a new leader among both internal and external candidates, while Muhlhauser plans to stay in the role until late 2015.
The announcement came as Celestica, which reports in U.S. dollars, said net earnings fell to US$34.4 million in the quarter, a steep decline from US$57.4 million in the comparable period last year.
On a per share basis, earnings were 19 cents compared with 31 cents in the same period last year.
The company, which provides global electronic manufacturing services to companies in several industry sectors, said revenues weakened nearly five per cent to $1.42 billion from $1.49 billion.
The weaker results came from "demand softness" in its communications division, Celestica said, adding that it expects the business environment to remain challenging in the near term.
"While we expect the overall business environment to remain challenging in the near term, we remain committed to investing for the future growth and profitability of Celestica," said Muhlhauser in a release.
The company estimates its fourth-quarter revenue will be in a range of $1.38 billion to $1.48 billion, with adjusted profits between 21 and 27 cents per share.
Celestica has operations in North America, Europe and Asia, specializing in the design, manufacture and assembly of electronics.
On the Toronto Stock Exchange, shares in the company, which reported after markets close, were up 21 cents or 1.91 per cent Tuesday at C$11.21.